Architectural paint and stain manufacturers typically distribute premixed paints and stains in a small number of popular colors. To accommodate consumer desires and enable matching of existing painted or stained surfaces, manufacturers typically also distribute a set of tintable base paints or stains and several concentrated colorants. These are combined at point-of-sale outlets using colorant dispensing and shaker mixing equipment to make small batch lots of custom-tinted paint or stain in a much larger array of colors than the limited color array available in premixed products.
Owing in part to industry custom and the available colorant dispensing equipment, the custom color systems from different paint or stain manufacturers tend to have somewhat similar components. For example, a typical custom color paint system may employ several (e.g., 2 to 4) tintable base paints ranging for example from a bright white base intended to accept at most a small quantity of colorant (viz., having a relatively small available headspace in the base paint container), to a relatively unpigmented clear base intended to accept a much larger quantity of colorant (viz., in a container initially containing for example about 9-10% less base than the bright white base and consequently having greater available headspace for colorant addition). Base paints and stains may employ various binders (e.g., natural or synthetic resins), binder forms (e.g., solution polymers or latex polymers) and vehicles (e.g., solvent-borne or water-borne versions), and may provide various dried surface finishes (e.g., matte, semi-gloss or gloss finishes). Some manufacturers also sell colored base paints (e.g. a red, a blue and yellow colored base) which are intended to be combined with additional colorant(s) when one coat hiding power is desired for strongly-tinted custom paint shades. The colorants in custom color paint or stain systems may for example be volumetrically metered from a multiple-colorant dispensing station, with 12 paint or stain colorants typically being employed in colorant dispensing stations for the U.S. market, and more (e.g., 16 or 24 colorants) sometimes being employed in other markets. The black colorant in such custom color systems typically contains a suspension of carbon black particles. Some paint bases are also shaded with carbon black to improve hiding. Carbon black is highly infrared-absorptive.
Homes and other buildings in tropical and other sunny regions normally are painted or stained in light colors to minimize solar gain. If tinted with some of the dark colorants employed in conventional custom color systems, the resulting paints or stains would in many cases be undesirably infrared-absorptive. Some paint manufacturers have developed premixed infrared-reflective external paints having dark colors, using relatively expensive infrared-reflective dark pigments. These premixed paints are available in a limited color palette.